William E. Halperin

Cancer mortality in workers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin

BACKGROUND In both animal and epidemiologic studies, exposure to dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin, or TCDD) has been associated with an increased risk of cancer. METHODS We conducted a retrospective cohort study of mortality among the 5172 workers at 12 plants in the United States that produced chemicals contaminated with TCDD. Occupational exposure was documented by reviewing job descriptions and by measuring TCDD in serum from a sample of 253 workers. Causes of death were taken from death certificates. RESULTS Mortality from several cancers previously associated with TCDD (stomach, liver, and nasal cancers, Hodgkins disease, and non-Hodgkins lymphoma) was not significantly elevated in this cohort. Mortality from soft-tissue sarcoma was increased, but not significantly (4 deaths; standardized mortality ratio [SMR], 338; 95 percent confidence interval, 92 to 865). In the subcohort of 1520 workers with greater than or equal to 1 year of exposure and greater than or equal to 20 years of latency, however, mortality was significantly increased for soft-tissue sarcoma (3 deaths; SMR, 922; 95 percent confidence interval, 190 to 2695) and for cancers of the respiratory system (SMR, 142; 95 percent confidence interval, 103 to 192). Mortality from all cancers combined was slightly but significantly elevated in the overall cohort (SMR, 115; 95 percent confidence interval, 102 to 130) and was higher in the subcohort with greater than or equal to 1 year of exposure and greater than or equal to 20 years of latency (SMR, 146; 95 percent confidence interval, 121 to 176). CONCLUSIONS This study of mortality among workers with occupational exposure to TCDD does not confirm the high relative risks reported for many cancers in previous studies. Conclusions about an increase in the risk of soft-tissue sarcoma are limited by small numbers and misclassification on death certificates. Excess mortality from all cancers combined, cancers of the respiratory tract, and soft-tissue sarcoma may result from exposure to TCDD, although we cannot exclude the possible contribution of factors such as smoking and occupational exposure to other chemicals.

Sentinel Health Events (occupational): a basis for physician recognition and public health surveillance.

A Sentinel Health Event(SHE)isa preventable disease, disability, oruntimely death whoseoccurrence serves asa warning signal thatthequality ofpreventive and/or therapeutic medical caremayneedtobeimproved. A SHE(Occupational) isa disease, disability, oruntimely death which isoccupationally related andwhoseoccurrence may:1)provide theimpetus forepidemiolog- icorindustrial hygiene studies; or2)serve asawarning signal that materials substitution, engineering control, personal protection, or medical caremayberequired. Thepresent SHE(O)list encom- passes 50disease conditions that arelinked totheworkplace. Only

Video Display Terminals and the Risk of Spontaneous Abortion

BACKGROUND The relation between spontaneous abortion and the use of video display terminals (VDTs) is of great public health concern. Previous investigators of this issue have reported inconsistent findings. METHODS To determine whether electromagnetic fields emitted by VDTs are associated with an increased risk of spontaneous abortion, a cohort of female telephone operators who used VDTs at work was compared with a cohort of operators who did not use VDTs. To obtain reliable estimates of exposure, we determined the number of hours of VDT use per week from company records and measured electromagnetic fields at VDT workstations and, for purposes of comparison, at workstations without VDTs. Operators who used VDTs had higher abdominal exposure to very-low-frequency (15 kHz) electromagnetic fields (workstations without VDTs did not emit very-low-frequency energy). Abdominal exposure to extremely-low-frequency fields (45 to 60 Hz) was similar for both operators who used VDTs and those who did not. Among 2430 women interviewed, there were 882 pregnancies that met our criteria for inclusion in the study. RESULTS We found no excess risk of spontaneous abortion among women who used VDTs during the first trimester of pregnancy (odds ratio = 0.93; 95 percent confidence interval, 0.63 to 1.38), and no dose-response relation was apparent when we examined the womens hours of VDT use per week (odds ratio for 1 to 25 hours per week = 1.04; 95 percent confidence interval, 0.61 to 1.79; odds ratio for greater than 25 hours per week = 1.00; 95 percent confidence interval, 0.61 to 1.64). There continued to be no risk associated with the use of VDTs when we accounted for multiple pregnancies, conducted separate analyses of early abortion, late abortion, and all fetal losses, or limited our analyses to spontaneous abortions for which a physician was consulted. CONCLUSIONS The use of VDTs and exposure to the accompanying electromagnetic fields were not associated with an increased risk of spontaneous abortion in this study.

Mortality among workers exposed to ethylene oxide.

BACKGROUND Ethylene oxide is a sterilant gas that causes leukemia and other cancers in animals. Studies in Sweden have shown an excess of leukemia and stomach cancer in humans exposed to ethylene oxide, but other studies have generally failed to confirm these findings. METHODS We conducted a study of mortality in 18,254 U.S. workers exposed to ethylene oxide at 14 plants producing sterilized medical supplies and spices. The subjects averaged 4.9 years of exposure to the gas and 16 years of follow-up. The exposure levels in recent years averaged 4.3 ppm (eight-hour time-weighted adjusted exposure) for sterilizer operators and 2.0 ppm for other workers. The levels in earlier years are likely to have been several times higher. Mortality in this cohort was compared with that in the general U.S. population. RESULTS Overall there was no significant increase in mortality from any cause in the study cohort. The standardized mortality ratios (SMRs) were 0.97 for leukemia (95 percent confidence interval, 0.52 to 1.67; 13 deaths observed), 1.06 for all hematopoietic cancers (95 percent confidence interval, 0.75 to 1.47; 36 deaths), and 0.94 for stomach cancer (95 percent confidence interval, 0.45 to 1.70; 11 deaths). Analyses according to job category and according to the duration of exposure showed no excess in cancers, as compared with the rate in the general population, but there was a significant trend toward increased mortality with increasing lengths of time since the first exposure for all hematopoietic cancers. The rate of death from hematopoietic cancer (especially non-Hodgkins lymphoma) was significantly increased among men (SMR, 1.55; 27 deaths). Mortality from leukemia in recent years (1985 through 1987) was significantly increased among men (SMR, 3.45; 5 deaths). CONCLUSIONS For the entire cohort, there was no increase in mortality from hematopoietic cancer. There was a slight but significant increase among men, however. Among men and women combined, there was a trend toward an increased risk of death from hematopoietic cancer with increasing lengths of time since the first exposure to ethylene oxide.

A comparison of the intradermal and subcutaneous routes of influenza vaccination with A/New Jersey/76 (swine flu) and A/Victoria/75: report of a study and review of the literature.

A trail of influenza vaccination, with use of bivalent split virus vaccine (A/New Jersey/76 and A/Victoria/75), was conducted to compare the immunogenicity and reactions when vaccine was given by the subcutaneous and intradermal routes. Volunteers 18 to 24 years old were randomized into equal groups, one group receiving 0.1 ml of vaccine intradermally and the other receiving 0.5 ml subcutaneously. For the A/Victoria vaccine, the immunogenicity of the intradermal route seemed superior; for A/New Jersey vaccine, the routes were equivalent. Adverse reactions were minimal and equivalent for both groups. In times of vaccine shortage, the intradermal route is considered to stretch vaccine supplies. Field trials of new influenza vaccines should include evaluation of the immunogenicity of and adverse reactions caused by the same vaccine given by different routes in varied dosages.

Conceptual and definitional issues in occupational injury epidemiology

This paper presents several models that further define the concept of occupational injury. While traditional models have proved successful in isolating specific research questions and health phenomena, the conceptual model presented permits a broader view of all injury morbidity. This model is based on both the level and frequency of energy transfers. A process model of occupational injury is also presented to describe the basic pathophysiological relationships associated with tissue effects/damage and recovery/repair. Numerous tradeoffs exist in variable selection, and a third model explores some of these tradeoffs. Differences in terminology and fundamental principles can limit the progress of occupational injury research. Accordingly, an argument is made for consolidation and consensus of terms. Finally, considerations for research are suggested, with an emphasis on the severity of the injury, the risk ratio, and the population at risk.

Green Tobacco Sickness: Occupational Nicotine Poisoning in Tobacco Workers

In this study the authors describe the investigation of a 1992 outbreak of green tobacco sickness, a form of nicotine poisoning from dermal exposure, among 47 tobacco workers in a five-county region of central and south-central Kentucky. Cases were identified through medical record searches at participating hospitals, as well as from reports submitted to the Occupational Health Nurses in Agricultural Communities program. A case-control study was undertaken to assess risk factors for green tobacco sickness. In a 20-min telephone interview, 40 cases and 83 controls responded to questions contained in a questionnaire. In 1992, 47 persons (3 were under age 16 y) in the study region sought medical treatment for green tobacco sickness. Twelve persons were hospitalized and 2 required intensive-care treatment. The crude incidence in 1992 was 10.0/1,000 tobacco workers. In 1993, 66 cases (7 were under age 16 y) of green tobacco sickness were identified in the study region (i.e., annual incidence of 14.0/1,000). A case-control study demonstrated that ill workers were younger, and were more likely to have worked in wet conditions, compared with workers who were not ill. Green tobacco sickness is a common problem among tobacco workers that may be prevented by avoiding work in wet tobacco or by use of protective clothing. Children younger than 16 y of age represented 9% of the green tobacco sickness cases in 1992 and 1993. Current occupational safety and health laws do not address protection of tobacco workers with respect to green tobacco sickness.

Options for occupational health surveillance of workers potentially exposed to engineered nanoparticles: state of the science.

Objective: Health authorities, employers, and worker representatives are increasingly faced with making decisions about occupational health surveillance of workers potentially exposed to engineered nanoparticles. This article was developed to identify options that can be considered. Methods: The published scientific literature on health effects from engineered and incidental nanoparticles and the principles of occupational health surveillance were reviewed to describe possible options and the evidence base for them. Results: Various options for occupational health surveillance were identified. The options ranged from no action targeted to nanotechnology workers to an approach that includes documentation of the presence of engineered nanoparticles, identification of potentially exposed workers, and general and targeted medical testing. Conclusions: Although the first priority should be to implement appropriate primary preventive measures, additional efforts to monitor employee health may be warranted. Continued research is needed, and the collection of such information for exposure registries may be useful for future epidemiologic studies.

Deaths due to injuries among employed adults: the effects of socioeconomic class.

Background. Few studies have investigated socioeconomic status (SES) and external causes of death (ie, deaths attributable to injuries). These deaths are of particular interest because they are potentially preventable and they represent the second leading cause of years of life lost under age 75. Methods. We studied 261,723 deaths from external causes in 27 states from 1984 to 1997 among employed persons age 20–64. Numerator data came from occupation on the death certificate. Occupation-specific denominator data came from the U.S. Census. A Nam-Powers SES score was assigned to each occupation based on its relative income and education in the U.S. Census. Results. After adjusting for age, sex, year and race, SES was strongly associated with mortality from all external causes combined for men (rate ratios = 2.9, 2.3, 1.5, and 1.0 by ascending SES quartile), and to a lesser extent for women (rate ratios = 1.6, 1.0, 1.1, and 1.0). A similar pattern was seen for each of the specific external causes (motor vehicle deaths, suicide, homicide, injuries other than by motor vehicle, and medical complications). Conclusions. We estimate 41% of deaths from external causes are attributable to having a SES below the top quartile (both sexes combined).

Occupation as a risk identifier for breast cancer.

OBJECTIVES Breast cancer mortality may be reduced if the disease is detected early through targeted screening programs. Current screening guidelines are based solely on a womans age. Because working populations are accessible for intervention, occupational identification may be a way of helping to define and locate risk groups and target prevention. METHODS We used a database consisting of 2.9 million occupationally coded death certificates collected from 23 states between 1979 and 1987 to calculate age-adjusted, race-specific proportionate mortality ratios for breast cancer according to occupation. We performed case-control analyses on occupational groups and on stratifications within the teaching profession. RESULTS We found a number of significant associations between occupation and frequency of breast cancer. For example, white female professional, managerial, and clerical workers all had high proportions of breast cancer death. High rates of breast cancer in teachers were found in both proportionate mortality ratio and case-control analyses. CONCLUSIONS These findings may serve as in an aid in the effective targeting of work-site health promotion programs. They suggest that occupationally coded mortality data can be a useful adjunct in the difficult task of identifying groups at risk of preventable disease.